<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
			.box {
				width: 200px;
				height: 200px;
				border: 1px solid red;
				display: flex;
				justify-content:center;
				align-items: center;
			}
			.item {
				width: 100px;
				height: 100px;
				border: 1px solid #000;
			}

		</style>
	</head>
	<body>
		<div class="box">
			<div class="item">
				
			</div>
		</div>
	</body>
</html>
